الفهرس 
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Abstract
The linear theory predicts that both the electromagnetic ion-cyclotron (EMIC) instability and the proton firehose (PFH) instability are fast enough to constrain the proton anisotropy, but the observations do not conform to the instability thresholds predicted by the standard theory for bi-Maxwellian models of the plasma particles, which are minimizing the contribution of the electrons by considering them isotropic and Maxwellian distributed. A refined analysis is presented in Chapters 3 and 4 for EMIC instability in the presence of anisotropic electrons and their suprathermal components. The growth rates, real frequencies, and threshold conditions are found to be highly sensitive to the electron temperature anisotropy and the electron-proton temperature ratio. Moreover, the suprathermal populations become an important factor that stimulates the effect of the anisotropic electrons. The first results of these analyses do not provide a good agreement with the proton observational data suggesting further refinements of the model. Thus, in Chapter 5 we invoke for the first time a dynamical model which correlate the anisotropic protons and electrons and capture the interplay of their instabilities. The new thresholds for both EMIC and PFH instabilities are found to be in a good agreement with the observations, even better than those obtained before for the aperiodic instabilities, but are highly conditioned by the electron properties. In Chapter 6 the investigations are extended by considering for the first time the interplay of the proton core and suprathermal halo, when both these two populations may exhibit temperature anisotropies, which destabilize the EMIC modes. Suprathermals enhance the high-energy tails of the velocity distributions making them well described by the Kappa distribution functions, with the advantage that these are power laws suitable to reproduce either the entire distribution or only the suprathermal halo tails. The new results clearly show that for conditions typically encountered in the solar wind, the effects of the suprathermals can be more important than those driven by the core. In Chapter 7 the analysis is extended for a more advanced model for the electron velocity distribution function, which is composed of a bi-Maxwellian core and a bi-Kappa suprathermal halo, and provides the dispersion relation for both the EFH and whistler instabilities. The new thresholds of the electron instabilities shape very well the limits of the anisotropy for both the electron core and halo populations with even larger k−indices than those in the zero-order approach.